Hi this is my first post. I recently cleared out the attic of my grandfather and came across two copy books. They are labeled house codes. I know he was involved in the IRA before world war 2 and was quite friendly with "the Germans " at the time. He is gone now but the little bit he did tell me was how proud he was to be part of reforming elements within the IRA into an acting army. With professionalism and order which he pinched from some German advisers. I have attached a picture there are many pages like this and I haven't a clue what they mean. I think he was in the dublin north city brigade or number 2 as he said but I'm not sure. Any ideas anyone?

Jeez that's a tough ask now, I'd say your best bet is to get onto someone in the Intelligence Section of the Irish Army, they might help you. Of course they might confiscate the book and you might disappear also.... but then if the 'Ra find out you're posting their secrets online they might try the same thing...

Well, best of luck anyway. And if we don't hear from you ever again we'll presume someone got to you!

This is quite an interesting find. It's also interesting that you recall your Grandfather being active in exciting militant republicanism once more. The 1930s was a defining decade for physical force republicanism. The IRA survived proscription by erstwhile comrades, Dev et all; a significant effort from within the movement to shift to the left, and embrace some form of social politics. Despite all this, the physical force strand of the movement succeeded, under the command of Sean Russell, and ultimately led to the S-Plan bombing campaign. 1939-40.

Moss Twomey was COS '26-'36. His papers are deposited in the UCD Archives, and contain a wealth of coded IRA correspondences. These were decoded and published by Thomas Mahon and James Gillogly in a book called 'Decoding the IRA'. There may be some correlation between this work and your Grandfather's copybook. On the other hand, there might not be, but it could be a sound starting point for you.

That is really fascinating. Perhaps the Dan Bryan papers may or may not be of some use as I believe there may be some information pertaining to Richard Hayes, who was a brilliant codebreaker and decoded German communications, but the UCD archives and/or the Military Archives should be able to help you out.